Method of dielectrically embossing a reflector button on a trim panel



June 4, 1968 J, J, MANCE ET AL 3,386,873

METHOD OF DIELECTRICALLY EMBOSSING A REFLECTOR BUTTON ON A TRIM PANELFiled May 15, 1963 2 Sheets-Sheet 1 {y UPPER ELECTRODE LOWER ELECTRODEATTO Ei June 4, 1968 MANcE ET AL 3,386,873

METHOD OF DIELECTR ICALLY EMBOSSING A REFLECTOR BUTTON ON A TRIM PANELFiled May 15, 1965 2 Sheets-Sheet F3 I I I U x United States Patent O3,386,873 METHOD OF DIELECTRICALLY EMBOSSING A REFLECTOR BUTTON ON ATRIM PANEL John J. Mance, Huntington Woods, and Ralph M. Stallard,Rochester, Mich., assignors to General Motors Corporation, Detroit,Mich., a corporation of Delaware Filed May 15, 1963, Ser. No. 280,681 6Claims. (Cl. 156-219) This invention pertains to a decorative reflectivearticle and a method for forming such article on the trim panel of anautomobile door.

The automotive industry has at times placed reflector buttons on trimpanels because, at nighttime, they serve to reflect the head-light beamsof an oncoming vehicle and thereby alert the driver to the danger of anopen door. Heretofore such buttons have been manufactured as sepa rateitems and frequently comprise a glass lens and metal support that ismechanically fastened to the trim panel. As should be apparent,areflector of this sort is relatively costly and its assembly to thetrim panel adds an additional operation in the fabrication of thelatter.

At present, it is common practice to form most of the trim panel by adielectric heating process which utilizes an alternating current ofradio frequency for generating heat in dielectric material. This processhas eliminated time-consuming operations such as sewing and providesbonding and embossment of the inner trim at substantial cost savingsover previously used methods. Because this is well recognized, it hasbecome increasingly important to utilize this process not only forforming decorative impressions in the cover sheet of the trim panel butalso for other uses which enhance the decorative appearance and functionof the panel. However, until now it has not been known how to form andbond a reflector button on a trim panel by dielectric embossing.

Accordingly, the principal object of this invention is to provide amethod for forming a reflector button on a trim panel by dielectricembossing.

Another object of the present invention is to provide a method forforming a thermoplastic reflecting portion and a metallic strip into areflector button by dielectric embossin g.

A further object of the present invention is to provide a method forbonding and forming a metallic molding on a thermoplastic base sheet bydielectric embossing.

These and other objects will be readily apparent from the followingdetailed description of the invention which was made with reference tothe drawings, in which:

FIGURE 1 is a schematic view taken on a vertical section of a dielectricheating press showing a trim panel and the components of a reflectorbutton positioned prior to embossment;

FIGURE 2 is an enlarged view of the embossing die construction and theelements of the reflector button at the closing of the press but priorto the application of pressure and high frequency electrical energy;

FIGURE 3 is a view similar to FIGURE 2 showing the reflector buttonafter the application of pressure and electrical energy;

FIGURE 4 is an enlarged view of a portion of the reflector button asseen in FIGURE 3;

FIGURE 5 is an isometric view showing the construc tion of the die andcomponents of the reflector button prior to emb ossment, and

FIGURE 6 is an isometric view illustrating the final article derivedfrom this process.

Referring now to FIGURE 1 of the drawings, a dielectric heating press isshown comprising an upper electrode 10 and a lower electrode12, both ofwhich are connected in series with a high frequency alternating currentgenerator 14. The upper electrode is movable through operat- PatentedJune 4, 1968 ice ing means, not shown, towards and away from the lowerelectrode while the generator is capable of impressing an alternatingcurrent at a frequency between one and megacycles between theelectrodes. This type of heaiing press is well known in the art andtherefore a detailed description regarding this press is not believed tobe necessary, however for further information regarding its operationreference is made to Dusin'a et 211. 2,946,713.

The lower electrode 12 rigidly supports a die construction 16 which asseen in FIG. 5 comprises a cylindrical embossing member 18 surrounded bya sleeve-type diffuser blade 20 that is seated on a coil spring 22resting on the upper surface of the electrode 12. The ditfuser bladepreferably is made from aluminum and has the upper end thereofterminating in a sharp annular point 24. In the normal position of thedie construction, the upper portion of the diffuser blade is elevated bythe coil spring slightly above the top surface of the embossing member18, as seen in FIG. 5.

The embossing member 18 is preferably made from stainless steel and, asseen in FIGS. 4 and 5, has the upper surface thereof formed with aplurality of concentric circular grooves 26 which progressively arelarger in diameter from the center of the embossing member toward theperiphery thereof. These grooves are equally and closely spaced fromeach other approximately .031 inch between centers so as to'form aplurality of circular inverted V- shaped concentric peaks 28 forpurposes to be explained hereinafter. Adjacent the periphery of theembossing member, an enlarged annular groove 30 which is arcuate incross-section, is formed so as to have a width substantially greaterthan any of the aforementioned grooves.

At this point, it should be mentioned that the abovedescribed dieconstruction and heating press are used in accordance with the inventionfor forming an ornamental reflector button on a base such as a trimpanel 32 of an automobile door. The reflector button is made from abezel portion 34 and a disc-shaped reflector portion 36 by thedielectric embossing process described below.

To practice the invention, initially the bezel portion 34 whichcomprises a precut metallic annulus 38 coated on one side thereof with athin sheet of polyvinylchloride 40 is positioned on the enlarged groove30 of the die construction 16 with the metallic portion of the bezelportion contacting the embossing member as shown in FIG. 2. It will beobserved that the outer diameter of the annulus is substantially thesame as the inner diameter of the diffuser blade 20 so that the latterserves to retain the bezel portion in the proper position with respectto the enlarged groove. In the preferred form, the annulus 38 consistsof a flat, thin strip of aluminum having a thickness between .002 and.010 inch.

Thereafter the reflector portion 36 of the reflector button ispositioned over the bezel portion and into the die construction as seenin FIG. 2. The body of the reflector portion is of a diameter slightlyless than the outer diameter of the bezel portion so that an annularportion of the coating 40 is exposed and notcovered by the reflectorportion. Four integral radially extending projections 42 of equal lengthare formed with the reflector portion and serve as locators forcontacting the inner wall of the diffuser blade 20 so as to centrallyposition the reflector portion within the die construction.

The reflector portion is preferably a preform comprising a transparentsheet 44 of acrylic resin such as methylmethacrylate which is bonded toan opaque sheet 46 of polyvinylchloride through a layer 48 of vinyladhesive which has a plurality of spherical glass beads or reflectingelements 50 embedded therein. The reflecting elements have a uniformdiameter of approximately .001 inch and are provided in suflicientnumber so as to, in effect, form a planar wall between the sheets 44 and46. This wall of beads or reflecting elements serve to reflect lightwhich passes through the sheet of acrylic resin.

After the bezel portion 34 and reflector portion 36 are positioned asshown in FIG. 2, a base sheet 52 made from a thermoplastic such aspolyvinylchloride is then placed on the die construction. As seen inFIG. 2, the base sheet 52 is the cover sheet of the trim panel 32 whichincludes a backing sheet 54 and a riser or filler material 56. Thebacking sheet can be made from a flexible material such as fabricsformed of cotton, wool, rayon, glass fibers, synthetic fibers, etc.,paper, leather, etc., as well as rigid and semi-rigid materials such ascomposition board, fiber board, paper laminates, synthetic sheets andmetals. The riser material should be made from a material capable oftaking a permanent set under the influence of heat and pressure. In thisinstance, the riser material is a felt material which consists of ablend of torn-up waste paper and rags suitably blended to providerequisite strength as described in Patent 3,052,587 in the name of R. L.Spieles and assigned to the assignee of this invention.

With the various parts being located, as seen in FIG. 2, the dielectricheating press is then closed by lowering the upper electrode towards thelower electrode 12 so as to compress the materials therebetween andcause the diffuser blade to retract. Thereafter, a pressure between 500and 1200 p.s.i. is applied to the sandwich of materials so as to permitthe embossing member 18 to partially deform the bezel portion 34 into anarcuate cross-section as seen in FIG. 3. An alternating electric fieldhaving a frequency between one and 100 rnegacycles is then impressedbetween the electrodes to heat the thermoplastic materials and permitembossement of the face of the sheet 44 into a plurality of concentricgrooves corresponding to those in the upper surface of the embossingmember. Simultaneously, the coating 46 is bonded to the sheet 44 andbase sheet 52, while the sheet 46 is also bonded to the lattermentionedbase sheet. Thus, the bezel and reflector portion are formed and bondedto the base sheet of the trim panel to form the ornamental reflectorbutton shown in FIG- URE 6.

An important feature of this invention is the simultaneous bonding andforming of the annulus 38 so as to simulate a rim or bezel around thereflector portion. As would be apparent to one skilled in the art, thisportion of the process can be utilized alone for purposes of formingmolding strips, ornamental buttons, etc., frequently preformed andmechanically fastened on the trim panels of an automobile. By utilizinga metallic element in accordance with the invention one achieves asecondary electrode during the process in a manner explained in detailin Patent No. 3,107,190. issued Oct. 15, 1963, and assigned to theassignee of this invention. Additionally, it should be noted that duringthe heating cycle, the thermoplastic layers interposed between theannulus 30 and the riser material 56 are softened and thereby permit theembossing member 18 to further form and embed the inner and outer edgesof the annulus into the trim panel. This, of course, is possible due tothe yieldable layers of material interposed between the annulus and thebacking sheet 54. In other words, in order to realize sufiicientdeformation of the annulus from an appearance standpoint, it isnecessary to have some form of yieldable material placed between thethermoplastic base sheet onto which the annulus is to be secured and theelectrode opposite to that contacting annulus.

Another significant feature of this invention is the embossment of thesheet 44 of acrylic resin by the embossing member so as to presentsurfaces that are inclined to the plane of the reflector portion. Asdescribed above, this is accomplished by providing the circular groovesin the surface of the acrylic sheet so as to form a series of invertedV-shaped peaks. Thus, where an obsenvers line of vision strikes the faceof the reflector button, light rays entering the reflector portion arediffused and reflected towards him by the glass beads. This isespecially important where the reflector button is formed on anautomobile door trim panel because it will permit the button to reflectlight whether the door is partially or fully open or anywhere betweenthese two positions.

Various changes and modifications can be made in the above-describedprocess without departing from the spirit of the invention. Accordingly,the inventor does not wish to be limited except by the scope of theappended claims.

What is claimed is:

1. A method of forming a reflector button on a dielectrically embossablethermoplastic base material from a preform comprising a sheet of acrylicresin bonded to a layer of glass beads and a sheet of vinyl bonded tothe glass beads, and a metallic element having a vinyl coating on oneside thereof, comprising the steps of placing the vinyl sheet of thepreform in contact with the base material, positioning the metallicelement so as to have its vinyl coating contacting the base material,applying a high frequency alternating voltage across the assembly tobond said vinyl sheet and coating to the base material, andsimultaneously embossing a plurality of grooves in said acrylic sheetand deforming said metallic element to simulate a lens mounted within asupport.

2. A method of forming a reflector button on a dielectrically embossablethermoplastic base material from a disk-shaped preform comprising asheet of acrylic resin bonded to a layer of glass beads and a sheet ofvinyl bonded to the glass beads, and a metallic annulus having a vinylcoating on one side thereof, comprising the steps of placing the vinylsheet of the preform in contact with the base material, positioning themetallic annulus so as to have its vinyl coating contacting the acrylicsheet and the base material, applying a high frequency alternatingvoltage across the assembly to bond said vinyl sheet and coating to thebase material, and simultaneously embossing a plurality of circularconcentric grooves in said acrylic sheet and deforming said annulus tosimulate a lens mounted within a support.

3. A method of forming and bonding a decorative metallic element on adielectrically embossable thermoplastic base material with a dielectricheating press having a pair of electrodes, comprising. the steps ofcoating a part of the element with a thermoplastic material, placingsaid element on said base material with the coating contacting said basematerial, deforming portions of said element between said electrodes soas to enhance the decorative appearance of said element, and applying ahigh frequency voltage between said electrodes to heat both of thematerials at the contacting surfaces thereof to fuse them together.

4. A method of forming and bonding a decorative metallic element on adielectrically embossable thermoplastic base material with a dielectricheating press having a pair of electrodes, comprising the steps ofcoating one surface of the element with a thermoplastic material,placing said element on said base material with the coating contactingsaid base material and positioning the composite on one of saidelectrodes, deforming the uncoated surface of said element underpressure of the other of said electrodes, and applying a high frequencyvoltage between said electrodes to heat both of the materials at thecontacting surfaces thereof to fuse them together.

5. A method of forming and bonding a decorative metallic element on adielectrically embossable thermoplastic base material with a dielectricheating press having a pair of electrodes, comprising the steps ofcoating one side of the element with a thermoplastic material, placingsaid element on said base material with the coating contacting said basematerial and positioning the composite on one of said electrodes,pressing portions of said element out of the plane of the latter andinto the base material under pressure of the other of said electrodes,and applying a high frequency voltage between said electrodes to heatboth of the materials at the contacting surfaces thereof to fuse themtogether.

6. A method of forming and bonding a decorative metallic element on adielectrically embossable thermoplastic base material with a dielectricheating press having a pair of electrodes, comprising the steps ofcoating one side of the element with a thermoplastic material, placingsaid element on said base material with the coating contacting said basematerial and positioning the composite on one of said electrodes,closing the press so that the other of said electrodes makes electricalcontact with the element, deforming portions of said element out of theplane of the latter and toward the base material under pressure of saidcontacting electrode, and applying a high frequency voltage between saidone of said electrodes and 6 the element to heat both of the materialsat the contacting surfaces thereof to fuse them together.

References Cited UNITED STATES PATENTS 3,078,179 2/1963 Kuhn et a1.156246 X 2,880,542 4/1959 Butterweich 161-5 2,958,148 11/ 1960 Sylvesteret al 161--34 3,046,179 7/1962 Stallard 156-273 X 2,464,826 3/1949 Neheret a1. 156322 X 2,993,806 7/1961 Fisher et al 11771 EARL M. BERGERT,Primazy Examiner.

H. F. EPSTEIN, Assistant Examiner.

1. A METHOD OF FORMING A REFLECTOR BUTTON ON A DIELECTRICALLY EMBOSSABLETHERMOPLASTIC BASE MATERIAL FROM A PREFORM COMPRISING A SHEET OF ACRYLICRESIN BONDED TO A LAYER OF GLASS BEADS AND A SHEET OF VINYL BONDED TOTHE GLASS BEADS, AND A METALLIC ELEMENT HAVING A VINYL COATING ON ONESIDE THEREOF, COMPRISING THE STEPS OF PLACING THE VINYL SHEET OF THEPREFORM IN CONTACT WITH BASE MATERIAL, POSITIONING THE METALLIC ELEMENTSO AS TO HAVE ITS VINYL COATING CONTACTING THE BASE MATERIAL, APPLYING AHIGH FREQUENCY ALTERNATING VOLTAGE ACROSS THE ASSEMBLY TO BOND SAIDVINYL SHEET AND COATING TO THE BASE MATERIAL, AND SIMULTANEOUSLYEMBOSSING A PLURALITY OF GROOVES IN SAID ACRYLIC SHEET AND DEFORMINGSAID METALLIC ELEMENT TO SIMULATE A LENS MOUNTED WITHIN A SUPPORT.